This invention relates to a radio frequency hair removal device and method for removing unwanted hair more effectively and permanently impairing future hair regrowth.
The most recent and more popular type of hair removal or epilator device that is currently in use is a tweezer type unit, through which RF energy is applied to the hair shaft. An example of one such device is shown in the Mehl U.S. Pat. No. 4,174,713.
This device is a hand-held tweezer type instrument to which radio frequency is applied. The hair is grasped between the tweezer tips and RF energy focused on the hair, through which it travels down to the hair papilla.
One of the important factors in effectiveness of such a device is the amount of RF energy that can be carried within the hair shaft and down to reach the hair papilla area at the hair shaft base. Ordinarily, the radio frequency energy is applied at a voltage of 100 to 300 peak to peak volts and has a frequency of 13.1, 27.1, or 40 megahertz. This radio frequency energy applied through the tweezer of the device shown in the Mehl U.S. Pat. No. 4,174,713 will usually bring about release and removal of the hair with damage to the hair papilla within two to ten seconds after RF energy is applied. This treatment time can be substantially reduced, or, the voltage itself greatly reduced, if the radio frequency which is applied to the hair is a frequency (resonant frequency) at which the particular hair has a reduced impedance to conduction of radio frequency energy. It has been found that the application of such a resonant frequency to the hair will substantially lower the voltage required to effect release and removal of the hair, and will still cause substantial damage to the hair papilla area.